1. Technical Field
The present invention relates generally to a tool holder for use with a rotary driver such as a drill and, more particularly, to an improved retaining mechanism for such a tool holder.
2. Discussion
Tool holders for rotary drivers such as drills are generally known in the art. Some tool holders directly couple bits, such as drilling bits or screw driving bits, to the rotary driver. Other holders couple reversible tools to the driver. U.S. Pat. No. 5,779,404 to Jore entitled xe2x80x9cReversible Drill/Driver Toolxe2x80x9d is representative of the latter holders.
Tool holders generally include a drive body having a shank at one end and a socket at the other. The socket is configured to accommodate the bit and a retaining mechanism is coupled to the socket to releasably couple the bit or bit holder to the socket for rotation with the tool holder. Prior art retaining mechanisms commonly include a retaining ball or spring that protrudes into the socket to couple the bit or bit holder to the socket. A sleeve or collar is axially movable along the socket between a locked position wherein the ball is maintained in its engaged position and an unlocked position wherein an annular recess in the sleeve or collar is aligned with the ball or spring to allow the ball or spring to move to a disengaged position and permit removal of the bit or bit holder from the socket.
One of the disadvantages of many prior art tool holders is that the sleeve or collar must be in its unlocked position to permit the bit to be moved into the socket. Accordingly, when an operator desires to couple the bit to the tool holder, the operator must first determine whether the sleeve is in its locked or unlocked position. If the sleeve is in its locked position, the operator must move the sleeve to its unlocked position prior to disposing the bit holder within the socket. Finally, after positioning the bit holder in the socket, the operator must move the sleeve to its locked position.
Further deficiencies in the prior art include retaining mechanism configurations that require two distinct movements to remove the bit holder from the socket. For example, some retaining mechanisms require rearward movement of the sleeve into its unlocked position followed by forward displacement of the bit holder away from the socket to effectuate removal. This bi-directional displacement sequence is undesirably inefficient.
It is an object of the present invention to provide a tool holder having a retaining mechanism that permits a bit to be disposed within and coupled to the socket when the retaining mechanism sleeve is in its locked position.
A further object of the present invention is to provide a retaining mechanism having a sleeve and a spring that normally biases the sleeve into its locked position thereby effectively retaining a bit in driving engagement with the socket when the bit is disposed therein.
Yet another object of the present invention is to provide a retaining mechanism having a key that is disposed within a slot in the socket for movement between an engaged position and first and second disengaged positions. The key is biased in its engaged position by a rubber o-ring and is in operative engagement with a retaining sleeve that is biased to its normal locked position yet moveable into an unlocked position. When the sleeve is in either its locked or unlocked positions, the sleeve is configured to permit the key to move to its first disengaged position to allow insertion of a bit within the socket. Further, the sleeve prevents movement of the key to its second disengaged position when the sleeve is in its normally locked position thereby retaining the bit holder to the socket.
A still further object of the present invention is to provide a retaining mechanism wherein the sleeve is rearwardly biased into its locked position such that forward movement of the sleeve against the bias places the sleeve in its unlocked position and allows the operator to displace the sleeve and the bit in the same axial direction and remove the bit from the socket in an efficient, and preferably one-handed, operation.
In view of the above, the present invention includes a tool holder for releasably coupling a bit with a non-circular outer connector surface to a rotary driver. The tool holder includes a socket and a retaining mechanism coupled to the socket and operable in a retaining mode and a released mode. The socket includes a forward end with an opening extending rearwardly from the forward end. The opening also includes a non-circular cross-section adapted to receive the outer connector surface of the bit to couple the bit for rotation with the socket. The retaining mechanism is adapted to permit disposable of the bit into an operative position within the opening and to prevent axial movement of the bit out of its operative position when the retaining mechanism is in its retaining mode. The retaining mechanism is further adapted to permit axial displacement of the bit out of its operative position when the retaining mechanism is in its released mode. The retaining mechanism includes a sleeve coupled to the socket for displacement toward the forward end of the socket from a locked position to an unlocked position thereby moving the retaining mechanism from its retaining mode into its released mode. The retaining mechanism also includes a spring biasing the sleeve into its locked position.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood however that the detailed description and specific examples, while indicating preferred embodiments of the invention are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the following detailed description.